This invention relates to a new improved PLAY SELECTOR control stereo tracks magnetic tape stereo recorder which solves the prior art inability to select one or the other of the stereo tracks when the stereo recorder is in record mode of operation. More particularly, the problem solved by the PLAY SELECTOR invention over prior art stereo recorders was that in the prior art each of the stereo recording heads is connected in circuitry with respective stereo recording amplifiers while the associated stereo erase heads are only connected in circuitry with a single erase oscillator circuit, thus no track selection due to the single erase circuit. Compare with: no track selection control of the dual erase heads shown disposed on two-way "dual tracks" via "switch 140" in FIG. 17 of the single-amplifier Dale patent 2,864,894 (1958); no track selection control of the dual erase heads shown disposed on two-way "dual tracks" via "switch 80" in FIG. 8 of my own single-amplifier patent 2,952,746 (1960); no track selection control of the sole erase head shown disposed across the respective stereo tracks in FIGS. 1, 2, and 3 of Nowlan patent 3,068,326 (1962); and no, track selection control of the sole erase head (not shown) disposed across both stereo tracks when the "grounded" playback "shorting switch 130" is operated in recording mode in FIG. 7 of Knoth patent 3,146,316 (1964). .Iaddend.
The present invention was first disclosed in my application entitled Four Track Magnetic Tape Recorders, Ser. No. 797,412, filed Mar. 5, 1959, now abandoned.
Copending applications related to this application are:
Bulk Tape Recording System, Ser. No. 830,356, filed July 29, 1959, now abandoned;
Means for Automatically Perforating and/or for Cutting Magnetic Tapes, Ser. No. 173,013, filed Feb. 13, 1962, now abandoned;
Central Control Console Means for Tape Recorders, Ser. No. 173,020, filed Feb. 13, 1962, now abandoned;
Stereo Tape Control Apparatus for a Slide Projector, Ser. No. 380,976, filed June 24, 1964, now Pat. No. 3,233,512 and its divisional application Ser. No. 418,087, filed Dec. 14, 1964 entitled Complete Technological Modernization of Education, now abandoned.
This invention relates to the art of magnetic tape recording devices and particularly concerns an improved magnetic tape recorder especially adapted for recording and reproducing sound on four tracks of a magnetic tape.
According to the invention there is provided a magnetic head assembly having four recording heads, each disposed to record and reproduce audio signals, on and from one channel of a four channel type. Associated with each magnetic head is a pair of erasing heads energized by a high frequency oscillator for erasing the signals recorded on any track just prior to re-recording signals thereon. A control circuit is associated with the various heads so that the system will record or pick up and reproduce signals from any one selected track, from any two tracks simultaneously, from a sequence of two pairs of tracks, and from any two or more tracks in any desired sequence. The system is provided with track, stereo, and sequence selector controls to effect the desired selection of recording and erasing head operations. The system also includes means to operate the apparatus continuously recording or reproducing signals on any selected sequence of tracks. The system further provides means for stopping operation automatically at the end of recording or reproducing signals from any track in any sequence of play.
The magnetic tape employed in the present system may be provided with metalized or electrically conductive leaders or trailers on opposite ends for coaction with sensing means and a solenoid operated switch serving as a motor controlling device. The solenoid is connected in a switching system and arranged for either manual or automatic control to effect the desired sequence of play of the various tracks. The sensing means makes possible automatic starting and reversing of the motor driven means for the tape. The solenoid switch further controls a step switch or counter for monitoring the number of tracks played in any predetermined sequence and stopping the recording or reproducing at the end of any such sequence or at an intermediate point therein, to resume operation again at that point if the operator so desires.
It is therefore a principal object of the invention to provide a magnetic tape recording and reproducing device employing four active recording tracks on the tape.
It is another object to provide a magnetic tape recording device having four or more recording tracks on the tape, and having control means for recording or reproducing signals from the tracks in any desired sequence.
It is still another object to provide a tape recording device which is selectively subject to manual, semi-automatic, or fully automatic control to record or reproduce signals from a plurality of tracks exceeding two in number, in any selected sequence of play.
It is a still further object to provide a multitrack tape recorder with counting means for monitoring a predetermined sequence of plays and for stopping the recorder when the sequence of plays is completed.
For further comprehension of the invention, and of the objects and advantages thereof, reference will be had to the following description and accompanying drawings, and to the appended claims in which the various novel features of the invention are more particularly set forth.